Carburetor



A Jan. 25, i927o www@ F. C. MQCK ET AL CARBURETOR Filed May 8. 1925 5 sheets-sheet 1 Jan. 25, 1927 1,615,398

y F. c. MocK ET AL CARBURETOR .-Filed May 8. 1925 l5 sheets-sheet s Jan 25 1927 F. c. MocK ET A.

CARBURETOR Filed My s, 1925 -5 sheets-sheet 4 H5398 IIL gli L6 9 Fa /59 wg? c. MQCK ET A1.

l CRBURETOR Filed May 8, 1925 5 Sheets-Sheet 5 f' l f www MMw/Mf,

Patented .Ja-n. 25,1927.- l

WUNirE-n* s iArEs .FRANK C. MCCK, CHARLES J; GUsTAFsoN, AND VMILTON E". CHANDLER, or CHICAGO, i ILLINOIS, AssIGNons'a-o gsrRoMBEnG vMoron DEVICES- CCMPANY, or CHICAGO, y

ILLINOIS, A CORPORATION OE ILLINOIS.

CARBURETOR. i

Our invention relates f to carburetors,l and,

I'in general, the Objectis to provide construc- 'such parts,

metal; v

.tionand arrangement which Will materially decrease the Weight', the manufacturing cost,

,and the-resistanceto flowv through the air inlet, carbureting' and outlet' passageways, and which .will increase the strength oftlie structure, give greater accessibility toA the vital and 4adjustable parts and greater. accuracy and convenience of adjustment of land which Willv provide greater convenience and practicability in the assem- 4bly of theivarious parts and will fullyprotect them. A

' More lin detail, an :important object of the invention is to niount the limportant and delicate fuel supply and controlling elements on asupporting body and'toenclose and protect them by a shell or housing'which providesthe air inlet, carbureting, and mixture outlet passageways, being of parts drawn from strong sheet Another important object of the invention -is to provide al Vfuel or iioat cup Idrawn from sheet steelto forma strong protecting housing for the fuel supply valve and its controlmeclianim. The formation of these various A operations,

forni and standard operation.'

, Another important object is lo pimivide forieady and easy separation of the body shell or housing from the supporting body so that the various fuel controlling and flow regulating Aparts are readily accessible for n i 18 forms a seat forthe conical lower end of' accurate inspection and adjustment.

' Other important features of our invention reside in the improved construction of varions controlling parts and' their Support on i t parts.

and connection with the sheet Inetal housing y Appiatiqn fried Mays,"

such shell 'or housing float and other fuel -regulating valve where the entire carburetor 1925. serial No. 28,771.

Referring to the drawings Figxl 1s a plan View of our improved .car-v buretor I* 1g. 2 isa side elevational view;

Fig. 3 is an elevationalview of thefiioat chamber side of the carburetor Fig. 4 is van elevational 4view of the oppositeside of the carburetor; r

.Figi 5 is a sectional viewon the plane 5-5ofFig.1; Fig.A 6 is an enlarged sectional view ofthe idling fuel jetv and its regulating mechanism.;

Fig. 7 is a sectional view on the 4.plane 7-'17 of Fig'. 5'; v l

l* ig. 8 is an enlarged sectional View en the plane 8 8 of Fig'.4 7;

F"g. 9 1s asectional viewA on the plane 9%9 of Fig. 5;v

Figa 10 is a sectional 10-10 of F ig. 7 g

view 'on the plane Fig. 1l is a sectional'view on the plane 'Fig 12`is a view, from plane 12-12 ofA Fig. 5' showing the inlet end-.of the idling nozzle.

" The inain body 1 of the carburetor is in the forin of a casting on one end. of'which isfsup-v ported the floatchamber or cup 2. In the 1 body part belowthe float cup.Y is thestrainer chamber 3. with which.communicates the inlet boss l connected by a fitting 5 with the pipe line leadingA to the gasoline supply tank.

The upper wall of the chamber 3 has the threaded opening 5 registeringl with' the opening 6 in the floor of the Heat cup, a plug 7 ertending through Vthe opening 6 and threading into the opening 5 and having the flange 8 for securelyilocking the ioat Cup on vthe body part, a gasket 9 of lead being pref@ erably interposed .in order to secure ay sealed fin? tion between the cup'and the strainer chamber. A. plug 10 threpf.N hito the bottom of the strainerchamber and serves as an abutment'for the spring 11 whichfliolds the strainer 12 securely against the top wall of the strainer chamber 'to strain fuel before it reaches the passageway 13 through lthe plug 7. -The upper end of the passageway the needle valve 14, the extension 15 on the .plug 7l forming aguide for the lower end of the valve. The float 16 surrounds the wai'dlyfrom the annular frame 18 which is lwhich is of sheet metal.

held in place by being clamped between the float cup bottom and the flange 8 of the plug 7. At its upper end the valve stem 14 has the' groove 19 receiving the inner ends of the fioat levers which are pivoted in ears 21 deflected out of the float cup cover 22 The groove part 19 forms part lof a sleeve 23 which receives the threaded upper end of thevalve stem' s o as to be adjustable thereon, a lock nut '24 securing the parts in adj ustedA position. The sleeve 23 extends beyond the cover 22 and through a threaded bushing 25v secured to the cover, a cap 26 engaging' the bushing to enclose and protect theupper end of the needle valve structure. This cap may. be provided with an atmosphere inlet opening 27 for` the flow of air through the bushing 25 and into the float chamber.

The fuel outfiow from the float chamber is controlled by the high speed needle valve 28 which extends'downwardl'y through the semi-circular enlargement or deflection 29 formed in the float chaiiibei wall. A valve seat plug 30 extends through the bottom of.

the float chamber and threads into the body part 1, its passageway communicating with the passageway 32 through the body part. The plug 8O assists the plug 7 in firmly holding the floatchamber against the top of the main body 1.

At its upper end, the needle valve 28 is secured in thelthreaded stem 33 extending from the head 84, the stem threading through the bushing 35 extending through and secured to the cover structure 22. The, circular wall 36 is secured between the bushing 35 and the cover and surrounds the head 34 and has latch grooves 37 in vwhich latch balls 38 engage to yieldingly .lock t-lie head 434 and consequently the valve with outlet ports 46.

28 lin any adjusted position.

The fuel passageway 32 leads to the bottom of the vertical well casing 39 which, intermediate its ends, supports the circular horizontal shelf 40. The `well casing 39 is threaded on its interior for the insertion from its lower end of the main nozzle structure 41 whose outlet end 42 extends from the upper end ofthe well casing, the nozzle structure having the axial bore 43 communicating at its lower end with the well 44 in the casing 39 below the nozzle structure. A- plug45 forms the bottom of the 'well 44.A The nozzle end 42 is shown as conical and is provided The housing Aor enclosing shell structures is composed of sections `drawn from sheet metal and intimately secured together. The l structure comprises the hood. section 47, the

` air inlet section 48,' and the coupling flange section 49. The hood sectionl is cylindrical and at its lower end seats on the circular shelf 40 to surround the well casing 69. The

hood part has the -vertical cylindrical extension 50 coaxial therewith but of reduced diameter, and the hood part has also the upper end of the reduced section 50 of the hood member, and having the transversely extending part 49b at its upper end for attachment with a companion coupling flange on the engine manifold. The flange part'49'J isf may be strengthened by a metal insert or filler 52. rl'he coupling flange section 49 is preferably rigidly secured to the part 50 by means of spot welding. Screws 53 extend through the top wall of the hood part 47 and threads into the shelf 40 to thus detachably hold the housing on the shelf in operative and protecting position.

Within the lower part of the extension 50 isl secured the main Venturi tube 54, and

in the upper part is the throttle valve 55 secured on the stem 56.. The tem 56 is journaled in bearing lugs 57 and 58 rigidly secured to the Ahousing part 49aby welding or otherwise. Secured 'to one end of the -stem are the stop beam 59 and the throttle lever 60, the wing 61 on the bearing lug 58 furnishing an abutment for the adjustable stop `screws 62 and 63..

' In the air inlet pipe 48 is the choke valve 64 secured on the stem 65 which'is jou'rnaled inthe bearing sleevestructures 66 and 67 secured to the pipe 48 by their flanges 68, as by spot welding. To one end of the stein is secured the choke lever 69, and to the bearing sleeve 67 is secured the holder arm '70 for the tube '71 which, in practice, 'runs to the dashboard and guides the operating wire 7 2 whose end is secured to therotatable head 78 on the choke lever 69.

On top of the extension-74 on the mainz body 1 is. mounted the small vVenturi tube 75 co-axially with the nozzle 41 and with the main venturi 54. The nozzle en d opens into the small venturi a short distancebe-A yond its throat, while the small venturi opens into the large Venturi tube a short distance beyond its' throat, as clearly shown in Fig. The small Venturi tube 75 has the lateral extension 76 over the body part l 74 and through openings in this extension extend the plug oi screw 78 and the tube"797 which tube, as will be explained later, forms a priming well. The -tube securely holds the small'Venturi structure on the body part 74, a gasket 80 preferably of soft metal being inserted to provide a seal fit.

The plug 78 threads into the body part 74 to bring itspassageway- 81 into communication with they passageway 82 in the part the housing structure S. 82 'in the bodypart- 74 is the passageway 84 leading down-V by thebleed inlet 88 vwith the interior of the.-

74, which passageway 82 leads through re the/throttle valve .duced openings v83 into the bore 48 lof the nozzle structurel 41, the passageway 82 together' withthe nozzle bore forming a high speed well whichis open at the top through the 'passageway 81 tothe pressure wwithin vBelow the passageway ,wardly to the top of the space 85 between the well casing 89 and the reduced diameter section of the nozzle structure 41, this space together with, the passageway forming 4an acceleratingwell. Extending into the upper end :of the passageway 84 is the screw 86 which has-the passageway 87 connected housing S. The head of -the screw. 8.6 engages the top vof the hood part 47 of the housing S and assists the screws in holding the housing securely on the shelf 40.

vThe space is connected with the nozzle bore through tiers' `of small passageways 89' for successively bleeding air into the nozzle bore to keep the fuel flowing from the bore. supplied with the proper amount of v air and toprevent excess Iflow or waste .of fuel. The ltube 79 threads at its lower cndinv the body part 7,4,a1`1dI extending axiallyl through the tube is the lowerpart 90 of the idling tube structure which' extends through the vbottom ot the supporting tube 79. and

' through the part 74 to the cross.` passageyindicated at 95.

way 91,connecte d by reduced 'passageways 92 with the nozzle/bore 43 near thebase of the nozzle.` The space -93 between the.'

tubes 7,9 and 90 forms a priming well which is connected with theA interior of thetube 90 through ports 94. the tube 90 being re# stricted just in advance of these ports, as The tube 79 above its threaded end is also displaced a distance from the bodypart 74 to leave additional priming well space 96 which communicates with the space 98'by ports 97. -The well 98 at its upper end is open to the interior ol the housing structure S.

The uppery section 98 of the idler tube structure is secured to and Adeper'ids from the idler nozzle supporting frame 90 which is secured against the side ofthe housing part 49' by screws 100. The tube vsection 98 at its lower' end extends tluoughthe hole 101 in 'the top of the hood part 4?, and telescopically receives the upper end of the lower idler t/ube section 90 when the housnozzle 104 is rotatable.

jects'through the ing passes through suitable opening'sinnthe side walls of the housing parts'` 50 and `49'.

bushing'107 'ttheend of the nozzle supporting. frame 99, v'vhich 'bush-.j

and assists the screws' 100 in 'securely holdy,

Y iiigth-efr'amef99in--placer-- The nozzle port `106 is atone side of the-nozleaxis, as' lclearly"'shown in Fig. 12 and terminates in a recess or transverse passageway formed by cutting away part of the nozzle end.I

`A tubular plug 109 "threads jinto the pocket 110 which cooperates with a springflll anda washer 11.2 to hold the nozzle headlwithin its seat 108. The nozzleA stern ll''e'xtends.

through the plug, and at its outer v,end has secured thereto the adjusting leyer .1 1'4. Be-

tween the h'eadof y.the plugv109alr'id theJ` body, 99 is'clamped'the quadrant ,plate 115 4having' a row of small notches 116 in thev path .of

the latch plunger 117 projectingfrom l'the barrel 118 carriedby the lever 114, tlielspgiilg;

119 yieldingly forcing the"plungerfagainst ther quadrant and sol serving to lock the idleif nozzle in any adjusted position. Toepreven't excessive swing vof the 1ever1114, stopextei-A sions 120 are provided at the lower corners.

of the quadrant plate for the abutment dcection 121` at the lower endof the'. lever 114.,

The operationl of the device When the engine is not operatingJhe gas'- oline is at normal level in the floatvchamber and the various wells and passageways conf. neeted therewith, as shownby line -a 'onthe drawings. For starting,or for idling or.

very low running, the throttle is closed;

Vhen the engine is now turned over, prac-1,

tically the entire suction 'effec-t ywill be c0115-,A

centrated on the idle nozzle port 106, andthe.

93, airto the amount of that which can travel through the recess 108|injthe idle plug,1ni"x' ing with the fuel, and this rich mixture;isy i Talle? priming well at its upper end is opentofthei inter1or of the housing S and when the-well drawn into the engine and starts .-itg;

is emptied of its charge ldown as far as the ports 94, -air will bleed into-the idler outlet Alube and then the suction effect will become effective at the idle well 91 for .supplying the fuel for idling oiyslow running, adjustnient being made by means ofthe levcrhlltv l connected nwith the idling nozzle. ln Figs. 6 and 12, the lever is shown in intermediate position with the port outlet opposite the throttle valve edge'and the air recess or passageway '108 vertical. `When the' lever and valve are rotated clockwise (Fig. 3), or.

counterclockwise (Fig. 12).. the port 106 will be raised above the throttle valve edge and will .then be more exposed to the suction ef fect above the throttle, and as the air 'pas sageway v108 vwill be correspondingly restrlcted, a richer mixture will ow to the enfuel will be drawn out of ,the priming well gine. When adjustment is made in the opposite direction, the idling port will be moved away from the suction effect and the mixture Will be leaner.

The choke valve 64 is operated in proper association with the idling system., With the primingwell incorporated in the idling system, the engine will usually start in the Warmer months of the year Without the use of the choke control. In colder Weather the vchoke control will be used in proper association with the throttle val-ve.

' For the higher or ordinary driving speeds,

the, throttle is opened and the main fuel nozzle becomes effective and supplies the necessary fuel. The Ahigh speed or main driving adjustment is re llated by the high speed needle valve 28lyvhich controls the ,flowl through the outletpassageway 3l from the.

fioat chamber. This needle valve is set for .the minimum outlet opening that will give smooth running and maximum engine speed under certain settings of the throttle and spark lever when adjustment is being made,

and then when the engine is driven it will operate efficiently throughout the ordinary range of speed.

When the throttle is opened to increase the speed after starting or idling, the. fuel in the upper end of the nozzle and Vin the Well 82 will be available for quick service, but assoon .as the ports 83 are uncovered any excess outflowof fuelwill be prevented, air fioiving down through the bleeder passage 81 I- inthe plug 78 and mixing With the fuel.

During ordinary running'of the engine there will be-.sufficient fuel at the upper end `of the nozzle to supply the demand. For a sudden unusual speed requirement or acceleration, the Well '85 becomes effective. Opening of the throttle inf accordance with the desire for such increased speed or accelerationwill result in corresponding increase in the suction effect and the air bleed passage- Way 81 will no longer be sufficient to satisfy the increased suction and fuel' will be taken up from deeper downin the nozzle passage- Way 43. However, excess fuel flow Will be prevented by the successive exposure of the ports 89 to air inflow through' the bleeder inlet 78 and lpassageway 84. The amount of.

air bled into the fuel flow is thus gradually increased until theproper -mixture will be established for efficient and economical running under acceleration. After such acceleration operation, the fuel willagain rise in the nozzleand restore normal condition. For `sudden acceleration demand the bleeder passages will -liag sufficiently in their control to permitdischarge from the nozzle of an adequate supply of fuel to efficiently meet the demand, but after the sudden demand is met,

the fuel ,flow falls back to normal in accordance with the effective operation of the bleeder ports.

`ing said well casing,

The carburetor shown has' no air. valves or metering needles, the air passages and fuel jets being all of fixed size for all engine I Its construction is such that the speeds. proper mixture is applied for all speeds, ex-

act setting being made possible by the pro# riininor char e when sheet metal parts, and the formation of the v float chamber from a single piece of sheet metal constitutes a radical departure in the manufacture of carburetors. It eliminates 'the liability of'loss in material and labor due to defective castings, and .materially rev duces the manufacturing cost. Another decided advantage of'such drawn sheet metall parts is that the extensive interior'surface of the air inlet and carbureting chambers is inherently smooth, thus greatly reducing the resistance to flow and correspondingly in'- creasing vthe efficiency*rr of the carburetor.

Such smooth uniform surface cannot be obtained in the ordinary cast carburetors Without expansive machine finishing Work. It

will also ybe* noted thaty with our improved constructionand arrangement, the fuel, flow controlling elements can 'be compacted and brought close Itogether so that drilling and i other fitting and finishing vvork will be re' duced `to a minimum. Furthermore, such compacting together of these elements makes adjustment more easy, and the elements are fully protected by the sheet metal housing structure which can Abe readily removed' from the carburetor body to expose the various elements for inspection andadjustment. Having described our invention, We claim as follows 1. A carburetor comprising an integral y cast body part, a vertical well casing forming part of said body part, a fuel nozzle Within said Well casing projecting 4from the,

upper end thereof, a shelf forming an `inte-` gral past of said body part and surrounda sheet,metal housing detachably mounted 'von said shelf to surround the Well casing andproviding an aii inlet and a mixture outlet, 4and asheet metal fuel container mounted on saidl body part adjacent to said shelf and having connection with 'said nozzle.

2. ln a carburetor, the combinationof a 'body part. in the form of an integral casting,

a vertical 'well casing at one end of said body part, a nozzle projecting through said Well casing,'a detachable fuel container at the other end of said housing, means for conducting fuel from said -container to-said nozzle, a shelfsurrounding said well casing, a support on said shelf adjacent Vsaid well casing, said support and 'shelf being integral with Vsaid body part, a vVenturi tube mounted on said'support to cooperate with said nozzle, and -a detachablehousing mounted on said shelf and providing an air inlet and a `mixture outlet passageway. A

3. In a carburetor, the combination of a body part, a fuel nozzle projecting upwardly at one end of said body part, a fuel container mounted on the other end of said body part for supplying fuel to said nozzle, a primary Venturi tube supported on said body part, a housing having detachable supports on said body part to enclose said nozzle, and Venturi tuben and providing an air inlet passageway andan outlet passageway, a secondf ary Venturi tube supported. in the outlet `passageway of said housing above said primary Venturi tube, and a throttle valve in said housing.

4. In a carburetor, the combination of a body, fuel controlling elements thereon, a fuel reservoir on said body,A and a housing detachably mounted on said body, said housing comprising a hood section receiving said fuel ,controllingielements an air inlet section, and a coupling section; said sections being integrally drawn from sheet metal vand intimately secured together.

5. In a carburetor, the combination of a body part, means thereon for ce olling fuel flow, and a housing for said fuel flow controlling means, said housing comprising a base section receiving vsaid fuel flow controlling means and a reduced outlet section, said housing being drawn integral from sheet'metal, said'base section having a lat- `eral flange, an air inlettube secured in said flange, a coupling part secured to saidl outlet section, and means within said reduced section for controlling the mixture outflow.

6. A carburetor comprising a body part, fuel supply andfuel control elements mounted thereon, and a sheet metal housing structure detachably mounted on said b'bdy,` said sageway, said base i air inlet.

housing comprising a base section receiving -said fuel controlling elements and having an extension forming a mixture outfiow pas- 7. In'a carburetor, the combination of a body part, a fuel supply and fuel discharge controlling elements mounted on said body part, and a housing part drawn integral 4from sheet metal and comprising a substan- 4tially-cyhnd'rical` base part and, aV reduced outlet section, said-A base section( receiving said fuel discharger controllingelements.

8. In a carburetor, -the combination of a body part, fuel Supplyand fuel discharge controlling eleinentsgniounted on -said body section having a lateral part, and a housing drawn integral from sheet metal and comprising a substantially cylindrical base section and a reduced outlet section, said base Section receiving-said fuel discharge controlling elements, said base section having a lateral flange deflected therefrom, and an air intake passage member secured in said flange. I

9. In a carburetor, the combination ofa supporting body, fuelsupply andfuel discharge controllingelements on said'body f part, and a drawn metal housingA structure detachably mounted on said body part, the

main part ofsaid housing structure having a substantially ycylindrical base for enclosing thefuel discharge controlling elements and having a cylindrical vertical outlet s'ecf tion of reduced diameter, said base having a lateral flange deflected rtherefrom forming a v 'lateral ing said outlet section. 10. Ina carburetor,

air inlet, and a vcoupling partreceivthe. combination of controlling elements supported on said -body part,l a tubularlsheet metal housing part providing lan outlet passageway at its upper end and having its loiver end expanded to form a hood for enclosing said fuel discharge controlling element, and an 'air inlet to said housing part.y

v 11. -In va carburetor, the combination of a body part, fuel supply and fuel discharge- `controlling elements supported on said body part, and a housing part formed from a single piece of sheet metal tubing, the upper end of said housing part .forming an outlet` passageway'and its lo`wer end being4 ex a body part, fuel supply and fuel discharge panded to form a hood for enclosing said fuel discharge controlling elements, and a v enforcing member receiving the upper/id of said main housing part and being eX-4 pandedat its upper end to form a coupling flange.

13. body part, fuelsupply and fuel discharge controlling 'elements supported thereon, and a housing structure, said housing structure comprising a main part formed from a single piece of sheet-metal tubing whose upper y end forms an outlt/ passageway and whose In -a carburetor, the combination of a cured in.v said flange', and a tubular relower end `is expanded to form a hood for enclosing said fuel supply and fuel discharge controlling elements, said hood pait having-l a flange laterally deflected therefrom, a tubular inlet member tclescopically secured in said flange, and a tubular reenforcing section telescopically receiving the upper end of said-.main part and expanded at its upper end to form a coupling flange.

14. In a carburetor, the combination' of a body part, fuel supply and fuel discharge controlling elements supported on said body part, a main housing part formed from a single piece,` of sheet metal tubing whose upper end provides a mixture outlet passageway and whose lower end is expanded to form an enclosing hood for said fuel`*'dis charge controlling elements', a flange def ilected laterally from said hood part, a tubular extension secured in said flange, an lair inlet controlling ine-ans in said extension, a tubular member receiving and strengthening Athe upper end of said main housing part i controlling and expanded at its upper end to form 'a coupling flange, a throttle valve "within the outlet passageway supported on said reenforced housing part, and fuel discharge mechanism mounted on said reenf'orced housing part and connected with said fuel discharge controlling mechanism" within said hood part.

115. In a carburetor, the combination of a body' part, fuel discharge controlling elements supported on said body part, a housing structure formed of drawn sheet metal part intimatelysecured together, said housing structure comprising a base section with a vertical outlet passageway and a lateral air inlet passageway, saidhousing structure be-` ing mounted on said body part with its base enclosing said fuel discharging controlling elements, a fu'el outlet controlling attachl ment at the outside of said housing structure` y and secured to the upper end thereof and supporting body part, fuel supply means supported on said body part, a main fuel nozzle supported on said body part and connected with said fuel supply means, a tubularsubstantially cylindrical housing structure detachably mounted-on said body part and having its lower end expanded to form 4 ahood for closing said main nozzle', the' upper end' of said housing forming an outlet `-passageway, an idli g well supported on said ody part within e hood of said housing structure and connected with said fuel supply means, an idling fitting outsideof and Y tube.

secured to the upper end of said housing structure, an idling nozzle 1n said fitting .communicating with said outlet passageway,

body part, fuel delivery elements mounted thereon, a fuel cup drawn integral from sheet metal supported on said body part, a vertical recess deflected in one side o f said cup, said body part having a passageway leading to said fuel delivery elements, a valve outlet connecting said cup with said passageway, and a valve extending inl said recess and operable from the top of said cup for controlling said valve out-let'.

18. In a carburetor, the combination-of a nozzle structure, a shelf thereon, a lateral extension on said nozzlestructure forming a support for fuel supply controlling wells, a small Venturi tube secured on said extension and in co-axial alignment with said nozzle struct-ure, a detachable sheet metal eni closure shell seated on said shelf concentric withsaid nozzle struct-ure and small Venturi tube, a large Venturi tube within said shell above said small Venturi tube, and a throttle .f'alve above said `large Venturi tube.

` 19. In a carburetor, the combination of 'a casting forming a nozzle structure and a lateral support thereon, a shelf on said casting,

a fitting detachably seating in said extension and forming a fuel supply controlling well, y

a small Venturi tube detacliably secured to sa'id, extension by lsaid fitting and positioned above said nozzle structure co-axial therewith, a sheet metal shell detachably applied v'on said shelf to surround said casting, the

upper end ofl Said shell being contracted to form an outlet passageway,1a large Venturi' tube in said outlet passageway above Asaid small Venturi tube, and a throttlevalve in said 20. In a carburetor, the"combiriation of a supporting casting, a circular shelf on said casting, a nozzle projecting above said shell',

.a well fitting adjacent to said nozzle, a detachable sheet metal shell seated on said shelf and enclosing at its lower end said nozzle and well fitting, the upper end f said passageway above said large Venturi shell being contracted to form a mixture out` l let passageway, a lthrottle valve in said outlet passageway, an idling plug structureV supported on the side of said contracted'shell part and having an idling outlet cooperat-v ing with said throttle valve, and a supply duct for-'saididling plug extending outside 1 of said contracted shell part and through the bottom part thereof into said-well tting.

21.l In a carburetor, the combination of a supporting casting, .a circular shelf on said casting,a nozzle projecting above said shelf, a well fitting adjacent to said nozzle, a detachable sheet metalshell seated on said'shelf nd enclosing at itslojwer endid nozzle and f well fitting, the upper end of said shell being contracted to form a mixture outlet pussageway, a throttle valve in said outlet pasv sageway, an idlingplg structure supported' on the side of saidcontracted shell part. sind .having an idling outlet cooperating with 'sid 'throttle valve, and a supply duct for said vidlinglplug extending outside of' said` duct beingjointed for permitting' separation 'of' said shell from said Shelf.

'In witness whereof, We hereunto subscribe our names this 4th dayof May, 1925.

, FRANK C. MOCK.

. CHARLES J. GUSTAFSON. MIL'IONE.v CHANDLER. 

